Teledermatology has emerged as an effective option to enhance the access of patients to high quality skin care in VA. VA's Office of Connected Care has developed two innovative mobile apps for VA teledermatology. One app, VA Telederm, streamlines the current workstation-based consultative process between primary care providers, teledermatology imagers and dermatologists, and is intended to lower the threshold for utilizing teledermatology in VA primary care clinics. The other app, My Telederm, will allow established dermatology patients to follow-up with VA dermatologists remotely rather than using in-person, clinic-based appointments. The app is intended to reduce the distances that appropriate established patients must travel to dermatology clinics and to improve the reliability of follow-up. It is also anticipated to free up appointment slots for new and established patients who actually must be seen in-person. The proposed research will test the hypothesis that successful implementation of each app will facilitate access of Veterans to dermatologic care. Each mobile app and its associated technical and clinical support resources will be rolled out in a stepped wedge cluster randomized trial design involving sites that are most likely to benefit from their use. The proposed research will compare outcomes for sites that have received the app to those that have not yet received it. Aim 1 will explicitly test the hypothesis by examining the following primary outcomes for both apps: 1) Measures of temporal access will be assessed by comparing intervention and control groups with respect to all dermatology consult and appointment completion times; 2) Measures of geographic access will include travel distance and rurality; 3) Measures of total access will be reflected in the total instances of care as reflected by the total numbers of dermatology/teledermatology encounters. In addition, outcome measures for the My Telederm app will also include timeliness of follow-up with respect to the target date, and the no-show rate, and the proportion of new patients in conventional dermatology clinics. Results will also be stratified by rurality. Aim 2 will examine the factors that affect successful implementation and impact of each app. Guided by the Replicating Effective Programs framework and Weiner's Organizational Theory of Implementation Effectiveness, we will conduct in-depth formative evaluations at 3 early adopter sites for each app to determine organizational, leadership, and end-user characteristics that correlate with implementation of the apps. In addition, using nationally and remotely available enterprise-wide data, we will measure implementation and adoption of apps at all participating sites. At the end of the study period, the proposed research will result in a novel documentation of mobile teledermatology's effectiveness in enhancing Veterans' access to dermatology services, as well as produce a comprehensive understanding of the factors leading to successful mobile telehealth implementation. The results will be of significance to VA as it develops and implements other mobile telehealth programs, and more generally to other healthcare organizations planning for large-scale telehealth interventions.